paper

Brightening of dark excitons in monolayers of semiconducting transition metal dichalcogenides

arXiv:1612.02867 · doi:10.1088/2053-1583/aa5521

Abstract

We present low temperature magneto-photoluminescence experiments which demonstrate the brightening of dark excitons by an in-plane magnetic field $B$ applied to monolayers of different semiconducting transition metal dichalcogenides. For both WSe $_{2}$ and WS $_{2}$ monolayers, the dark exciton emission is observed at $\sim$ 50 meV below the bright exciton peak and displays a characteristic doublet structure which intensity is growing with $B^{2}$ , while no magnetic field induced emission peaks appear for MoSe $_{2}$ monolayer. Our experiments also show that the MoS $_{2}$ monolayer has a dark exciton ground state with a dark-bright exciton splitting energy of $\sim$ 100 meV.

7 pages, 3 figures